Bumper collision sensor for an automotive vehicle

ABSTRACT

An automotive vehicle includes a vehicle body and a fascia coupled to the vehicle body. The vehicle also includes a rigid backer plate coupled to the body. The backer plate is disposed between the body and the fascia, and is spaced from the fascia. The vehicle further includes a compressible layer disposed between the fascia and the backer plate. The compressible layer has a first face proximate the fascia and a second face proximate the backer plate. The second face is provided with a recess to define a cavity between the compressible layer and the bumper plate. A pressure sensor is disposed in the cavity. The rigid backer plate has a backer plate face proximate the compressible layer and a rib member projecting from the backer plate face. The rib member is disposed at least partially in the cavity.

TECHNICAL FIELD

The present disclosure relates to automotive vehicles, and moreparticularly to bumper structures of automotive vehicles.

INTRODUCTION

In conventional automotive vehicles, a variety of protective devices maybe implemented. One such protective device is a collision sensor.Collision sensors may be provided in various locations on the vehicleand be configured to detect an impact between the vehicle and an objectexternal to the vehicle. Among the known types of collision sensors areaccelerometer-based collision sensors, which detect a collision based onacceleration of the vehicle, and pressure-based collision sensors, whichdetect a collision based on an increased pressure applied to the sensor.

SUMMARY

An automotive vehicle according to the present disclosure includes avehicle body. The body has a width direction. The vehicle additionallyincludes a fascia coupled to the vehicle body. The fascia has a longdimension oriented in the width direction. The vehicle also includes arigid backer plate coupled to the body. The backer plate is disposedbetween the body and the fascia, and is spaced from the fascia. Thevehicle further includes a compressible layer disposed between thefascia and the backer plate. The compressible layer has a first faceproximate the fascia and a second face proximate the backer plate. Thesecond face is provided with a recess to define a cavity between thecompressible layer and the bumper plate. The recess has a long dimensionoriented in the width direction. A pressure sensor is disposed in thecavity. The rigid backer plate has a backer plate face proximate thecompressible layer and a rib member projecting from the backer plateface. The rib member is disposed at least partially in the cavity.

In an exemplary embodiment, the rib member has a first end, a secondend, and a central portion between the first end and the second end. Atthe first end the rib member projects a first distance from the backerplate face, and at the central portion the rib member projects a seconddistance from the backer plate face. The second distance is differentfrom the first distance.

In an exemplary embodiment, the rib member has a generally rectangularcross-section.

In an exemplary embodiment, the rib member is provided with a concavetip proximate the pressure sensor.

In an exemplary embodiment, the rib member is provided with a convex tipproximate the pressure sensor.

In an exemplary embodiment, the pressure sensor includes a pressure tubeextending along the width direction.

A bumper assembly according to the present disclosure includes a fascia,a rigid backer plate spaced from the fascia, and a compressible layerdisposed between the fascia and the backer plate. The compressible layerhas a first face proximate the fascia and a second face proximate thebacker plate. The second face is provided with a recess to define acavity between the compressible layer and the backer plate, with apressure sensor disposed in the cavity. The rigid backer plate has abacker plate face proximate the compressible layer and a rib memberprojecting from the backer plate face. The rib member is disposed atleast partially in the cavity.

In an exemplary embodiment, the rib member has a first end, a secondend, and a central portion between the first end and the second end. Atthe first end the rib member projects a first distance from the backerplate face, and at the central portion the rib member projects a seconddistance from the backer plate face. The second distance is differentfrom the first distance.

In an exemplary embodiment, the rib member has a generally rectangularcross-section.

In an exemplary embodiment, the rib member is provided with a concavetip proximate the pressure sensor.

In an exemplary embodiment, the rib member is provided with a convex tipproximate the pressure sensor.

In an exemplary embodiment, the pressure sensor includes a pressure tubeextending along the width direction.

A sensor assembly for an automotive vehicle includes a vehicle body anda bumper assembly coupled to the vehicle body. The bumper assemblyincludes a fascia and a compressible layer disposed between the fasciaand the vehicle body. A rigid backer plate is disposed between the bodyand the compressible layer. The compressible layer is provided with arecess to define a cavity between the compressible layer and the backerplate, and the backer plate is provided with a backer plate face and arib member projecting from the backer plate face. The rib member isdisposed at least partially in the cavity. The assembly also includes apressure sensor with a pressure tube disposed at least partially in thecavity.

In an exemplary embodiment, the rib member has a first end, a secondend, and a central portion between the first end and the second end. Atthe first end the rib member projects a first distance from the backerplate face, and at the central portion the rib member projects a seconddistance from the backer plate face. The second distance is differentfrom the first distance.

In an exemplary embodiment, the rib member has a generally rectangularcross-section.

In an exemplary embodiment, the rib member is provided with a concavetip proximate the pressure sensor.

In an exemplary embodiment, the rib member is provided with a convex tipproximate the pressure sensor.

In an exemplary embodiment, the pressure sensor includes a pressure tubeextending along the width direction.

Embodiments according to the present disclosure provide a number ofadvantages. For example, the present disclosure provides a system andmethod for collision detection which may be easily adapted according todetection requirements.

The above and other advantages and features of the present disclosurewill be apparent from the following detailed description of thepreferred embodiments when taken in connection with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustrative view of an automotive vehicle according to anembodiment of the present disclosure;

FIG. 2 is a schematic illustration of an automotive vehicle according tothe present disclosure;

FIG. 3 is a cross-sectional view of a bumper assembly according to anembodiment of the present disclosure;

FIGS. 4A-4C are cross-sectional views of sensor assemblies according tovarious embodiments of the present disclosure;

FIG. 5 is an isometric view of a rigid plate member according to anembodiment of the present disclosure; and

FIGS. 6A-6C are cross-sectional views along section line 6-6 of FIG. 5according to various embodiments of the present disclosure.

DETAILED DESCRIPTION

Embodiments of the present disclosure are described herein. It is to beunderstood, however, that the disclosed embodiments are merely examplesand other embodiments can take various and alternative forms. Thefigures are not necessarily to scale; some features could be exaggeratedor minimized to show details of particular components. Therefore,specific structural and functional details disclosed herein are not tobe interpreted as limiting, but are merely representative. The variousfeatures illustrated and described with reference to any one of thefigures can be combined with features illustrated in one or more otherfigures to produce embodiments that are not explicitly illustrated ordescribed. The combinations of features illustrated providerepresentative embodiments for typical applications. Variouscombinations and modifications of the features consistent with theteachings of this disclosure, however, could be desirable for particularapplications or implementations.

Referring now to FIG. 1, an automotive vehicle 10 according to anembodiment of the present disclosure is illustrated. The vehicle 10 hasa body 12. At least one bumper 14 is coupled to the body 12. A frontbumper 14 is shown at a fore portion of the body 12 in FIG. 1, and aback bumper 14 may also be provided at an aft portion of the body 12. Apressure sensor assembly 16 is retained within the bumper 14, as will bediscussed in further detail below. The pressure sensor assembly 16 isconfigured to generate a pressure signal based on pressure applied tothe pressure sensor assembly 16.

In an exemplary embodiment, the pressure sensor assembly 16 includes apressure tube extending generally along a width direction W of thevehicle 10. Such pressure tubes are compressible tubes formed of, forexample, silicone, and filled with a fluid such as air. A pressuresensor is provided at one or both ends of the pressure tube andconfigured to measure pressure of the fluid within the tube. In responseto compression of the tube, the pressure of the fluid increases, and thepressure sensor or sensors generate a signal indicative of the pressureincrease.

The pressure sensor assembly 16 may be arranged generally linearlyacross the bumper 14, or in a non-linear profile as illustrated inFIG. 1. Advantageously, a non-linear profile may enable more responsivecollision detection at different heights of the bumper 14.

Referring now to FIG. 2, the vehicle 10 is schematically illustrated.The pressure sensor assembly 16 is in communication with at least onecontroller 17. While depicted as a single unit, the controller 17 maycomprise multiple controller units collectively be referred to as a“controller.” The controller 17 may include a microprocessor or centralprocessing unit (CPU) in communication with various types of computerreadable storage devices or media. Computer readable storage devices ormedia may include volatile and nonvolatile storage in read-only memory(ROM), random-access memory (RAM), and keep-alive memory (KAM), forexample. KAM is a persistent or non-volatile memory that may be used tostore various operating variables while the CPU is powered down.Computer-readable storage devices or media may be implemented using anyof a number of known memory devices such as PROMs (programmableread-only memory), EPROMs (electrically PROM), EEPROMs (electricallyerasable PROM), flash memory, or any other electric, magnetic, optical,or combination memory devices capable of storing data, some of whichrepresent executable instructions, used by the controller in controllingthe engine or vehicle.

The vehicle 10 additionally includes at least one protection system 19and a wireless communication system 21. The protection system or systems19 and the wireless communication system 21 are in communication with orunder control of the controller 17. The protection system 19 includesone or more of a variety of systems for protecting occupants within thevehicle 10, pedestrians external to the vehicle 10, other objectsexternal to the vehicle 10, or a combination thereof. As non-limitingexamples, the protection system 19 may include an interior airbag or aircurtain mounted to a steering wheel or interior panel of the vehicle, anexterior airbag mounted to an exterior portion of the vehicle forpedestrian protection, a seatbelt tensioning system, other protectivedevice, or any combination thereof. The wireless communication system 21is configured to communicate wirelessly with other vehicles orinfrastructure and may include, for example, a cellular communicationmodem, a dedicated short-range communication (DSRC) modem, an IEEE802.11 communication modem, other wireless communication device, or anycombination thereof.

The controller 17 is programmed to, in response to a signal from thepressure sensor assembly 16 indicating that the vehicle 10 has collidedwith an object external to the vehicle 10, control the protection system19 to activate for protection of occupants and/or pedestrians or objectsin the vicinity of the vehicle 10. The controller 17 may be programmedto transmit a collision alert via the wireless communication system 21.Such alerts may indicate to other vehicles, emergency responsepersonnel, or other entities that a collision has occurred. In somealternative embodiments, no wireless communication system is provided.

Referring now to FIG. 3, a cross-section of the bumper 14 is illustratedschematically. The bumper 14 includes a fascia 18. The fascia 18 isgenerally rigid and may form the exterior of the bumper 14. The bumper14 is secured to a structural member 20 of the body 12. The structuralmember 20 may include a body beam, tie bar, or any other suitableattachment feature of the body 12.

A compressible layer 22 is provided between the fascia 18 and thestructural member 20. The compressible layer 22 is configured to deformor compress during a collision and may include, for example, a foammaterial or plastic honeycombed structure. The compressible layer 22 maythereby absorb energy during a collision.

A rigid plate 24 is disposed between the compressible layer 22 and thestructural member 20. The rigid plate 24 may be formed of, for example,a rigid plastic material, a metallic material, or any other suitablyrigid material. The rigid plate 24 may be secured to the structuralmember 20 or to the fascia 18 via fasteners, adhesives, welding, or anyother suitable joining method. While the rigid plate 24 and structuralmember 20 are illustrated as distinct components in FIG. 3, inalternative embodiments the rigid plate 24 and structural member 20 maybe formed as an integral component.

A groove is formed in the face of the compressible layer 22 adjacent tothe rigid plate 24. A cavity 26 is thereby defined between thecompressible layer 22 and the rigid layer 24. At least a portion of thepressure sensor assembly 16 is disposed in the cavity 26. In theillustrated embodiment, a pressure tube of the pressure sensor assembly16 is disposed in the cavity 26; however, in embodiments implementingother types of pressure sensors, other portions of the pressure sensorassembly 16 may be disposed in the cavity 26. Furthermore, while thepressure tube is illustrated as being round in cross-section, in otherembodiments the pressure tube may take alternate shapes.

A rib member or flange 28 projects from the face of the rigid plate 24adjacent to the compressible layer 22. The rib member 28 is disposed atleast partially within the cavity 26.

In the case of a collision between the bumper 14 and an object externalto the vehicle 10, the fascia 18 may impart pressure to the compressiblelayer 22. The compressible layer 22 will compress under the pressure, atleast partially collapsing the cavity 26 and driving the portion of thepressure sensor assembly 16 into contact with the rib member 28. Thepressure sensor assembly 16 may then generate a signal indicative of thepressure increase, in response to which the controller 17 may determinethat the collision has occurred.

As may be seen, the rib member 28 provides a reaction surface for thepressure sensor assembly 16, which may increase the responsiveness ofthe pressure sensor assembly 16 relative to known solutions. Moreover,the shape and profile of the rib member 28 may be tuned to providedesired response characteristics for a given application, as will bediscussed in further detail below. Furthermore, the rigid plate 24 mayextend outboard of the structural member 20, thereby increasing width ofthe reaction surface.

Referring now to FIGS. 4A through 4C, various profile shapes areillustrated. In FIG. 4A, a rib member 30 having a convex arcuate profileis illustrated. In FIG. 4B, a rib member 32 having an angular convexprofile is illustrated. In FIG. 4C, a rib member 34 having a concavearcuate profile is illustrated. Different profile shapes may providedifferent response characteristics. As an example, the concave ribmember 34 may compress the pressure assembly 16 more rapidly than theconvex rib members 30 or 32.

Moreover, as illustrated in FIGS. 5, 6A, 6B, and 6C, the height of therib member may be tuned to provide desired response characteristics. Asshown in FIG. 5, a rigid plate 24′ is provided with a rib member 28′.The rib member 28′ extends generally in a width direction from a firstend 36 to a second end 38. The rib member 28′ may extend linearly, ormay have a non-linear profile as illustrated in FIG. 5. Advantageously,a non-linear profile may enable more responsive collision detection atdifferent heights as discussed above in FIG. 1. The height of the ribmember 28′ may, in various embodiments, be generally constant betweenthe first end 36 and the second end 38 as illustrated in FIG. 5, or mayvary between the first end 36 and the second end 38 as discussed belowin conjunction with FIGS. 6 A through 6C. As used here, the heightrefers to the distance from the rigid plate 24′ to which the rib member28′ projects.

Referring now to FIG. 6A, a first exemplary rib profile is illustrated.In this embodiment, the backer plate 24″ is provided with a rib member28″ having a first height h₁ at a first end 36′, a second height h₂ at acentral portion between the first end 36′ and second end 38′, and athird height h₃ between the first and second ends 36′, 38′ and thecentral portion. The third height h₃ is less than the first height h₁,and the second height h₂ is less than the third height h₃. The ribmember 28″ thereby has a stepped height profile, with a greater heightat the first and second ends 36′, 38′ than at the central portion. Sucha rib profile may increase response of the pressure sensor assemblyproximate the first and second ends 36′, 38′. This may advantageouslyoffset attenuation in pressure response near edges of the bumper causedby energy loss due to deflection.

Referring now to FIG. 6B, a second exemplary rib profile is illustrated.In this embodiment, the backer plate 24′″ is provided with a rib member28′″ having a fourth height h₄ at a first end 36″, a fifth height h₅ ata central portion between the first end 36″ and second end 38″, and asixth height h₆ between the first and second ends 36″, 38″ and thecentral portion. The fourth height h₄ is less than the sixth height h₆,and the sixth height h₆ is less than the fifth height h₅. The rib member28′″ thereby has a stepped height profile, with a lesser height at thefirst and second ends 36″, 38″ than at the central portion. Such a ribprofile may increase response of the pressure sensor assembly proximatethe central portion.

Referring now to FIG. 6C, a third exemplary rib profile is illustrated.In this embodiment, the backer plate 24″ is provided with a rib member28″ having a seventh height h₇ at a first end 36″, an eighth height h₈at a central portion between the first end 36′″ and second end 38″, anda ninth height h₉ between the first and second ends 36″, 38′″ and thecentral portion. The ninth height h₉ is less than the seventh height h₇and the eighth height h₈. Such a rib profile may increase response ofthe pressure sensor assembly proximate the central portion and at firstand second ends.

While FIGS. 6A through 6C illustrate rib profiles having five segmentsof discontinuous heights, any number of segments may be used and/or theheight of the rib profile may vary continuously between adjacentsegments.

As may be seen, the present disclosure provides a system for detecting acollision between a vehicle and an object external to the vehicle, andmoreover does so while providing an easy mechanism for tuning thedesired response of the collision sensor.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms encompassed by the claims.The words used in the specification are words of description rather thanlimitation, and it is understood that various changes can be madewithout departing from the spirit and scope of the disclosure. Aspreviously described, the features of various embodiments can becombined to form further exemplary aspects of the present disclosurethat may not be explicitly described or illustrated. While variousembodiments could have been described as providing advantages or beingpreferred over other embodiments or prior art implementations withrespect to one or more desired characteristics, those of ordinary skillin the art recognize that one or more features or characteristics can becompromised to achieve desired overall system attributes, which dependon the specific application and implementation. These attributes caninclude, but are not limited to cost, strength, durability, life cyclecost, marketability, appearance, packaging, size, serviceability,weight, manufacturability, ease of assembly, etc. As such, embodimentsdescribed as less desirable than other embodiments or prior artimplementations with respect to one or more characteristics are notoutside the scope of the disclosure and can be desirable for particularapplications.

What is claimed is:
 1. An automotive vehicle comprising: a vehicle bodyhaving a width direction; a fascia coupled to the vehicle body, thefascia having a long dimension oriented in the width direction; a rigidbacker plate coupled to the body, the backer plate being disposedbetween the body and the fascia and being spaced from the fascia; acompressible layer disposed between the fascia and the backer plate, thecompressible layer having a first face proximate the fascia and a secondface proximate the backer plate, the second face being provided with arecess to define a cavity between the compressible layer and the backerplate, the recess having a long dimension oriented in the widthdirection; and a pressure sensor disposed in the cavity; wherein therigid backer plate has a backer plate face proximate the compressiblelayer and a rib member projecting from the backer plate face, the ribmember being disposed at least partially in the cavity, the rib memberhaving a length extending generally parallel to the width direction andhaving, along the length, a first portion, a second portion, and acentral portion between the first portion and the second portion,wherein at the first portion the rib member projects a first distancefrom the backer plate face, and at the central portion the rib memberprojects a second distance from the backer plate face, the seconddistance being different from the first distance.
 2. The automotivevehicle of claim 1, wherein the rib member has a first end, a secondend, the first portion is disposed at the first end, and the secondportion is disposed at the second end.
 3. The automotive vehicle ofclaim 1, wherein the rib member has a generally rectangularcross-section.
 4. The automotive vehicle of claim 1, wherein the ribmember is provided with a concave tip proximate the pressure sensor. 5.The automotive vehicle of claim 1, wherein the rib member is providedwith a convex tip proximate the pressure sensor.
 6. The automotivevehicle of claim 1, wherein the pressure sensor includes a pressure tubeextending along the width direction.
 7. A bumper assembly comprising: afascia; a rigid backer plate spaced from the fascia; a compressiblelayer disposed between the fascia and the backer plate, the compressiblelayer having a first face proximate the fascia and a second faceproximate the backer plate, the second face being provided with a recessto define a cavity between the compressible layer and the backer plate;and a pressure sensor disposed in the cavity; wherein the rigid backerplate has a backer plate face proximate the compressible layer and a ribmember projecting from the backer plate face, the rib member beingdisposed at least partially in the cavity, the rib member having alength extending generally parallel to the width direction and having,along the length, a first portion, a second portion, and a centralportion between the first portion and the second portion, wherein at thefirst portion the rib member projects a first distance from the backerplate face, and at the central portion the rib member projects a seconddistance from the backer plate face, the second distance being differentfrom the first distance.
 8. The bumper assembly of claim 7, wherein therib member has a first end, a second end, the first portion is disposedat the first end, and the second portion is disposed at the second end.9. The bumper assembly of claim 7, wherein the rib member has agenerally rectangular cross-section.
 10. The bumper assembly of claim 7,wherein the rib member is provided with a concave tip proximate thepressure sensor.
 11. The bumper assembly of claim 7, wherein the ribmember is provided with a convex tip proximate the pressure sensor. 12.The bumper assembly of claim 7, wherein the pressure sensor includes apressure tube.
 13. A sensor assembly for an automotive vehicle,comprising: a vehicle body; a bumper assembly coupled to the vehiclebody, the bumper assembly including a fascia and a compressible layerdisposed between the fascia and the vehicle body; a rigid backer platedisposed between the body and the compressible layer, wherein thecompressible layer is provided with a recess to define a cavity betweenthe compressible layer and the backer plate, and wherein the backerplate is provided with a backer plate face and a rib member projectingfrom the backer plate face, the rib member being disposed at leastpartially in the cavity, the rib member having a length extendinggenerally parallel to the width direction and having, along the length,a first portion, a second portion, and a central portion between thefirst portion and the second portion, wherein at the first portion therib member projects a first distance from the backer plate face, and atthe central portion the rib member projects a second distance from thebacker plate face, the second distance being different from the firstdistance; and a pressure sensor comprising a pressure tube disposed atleast partially in the cavity.
 14. The sensor assembly of claim 13,wherein the rib member has a first end, a second end, the first portionis disposed at the first end, and the second portion is disposed at thesecond end.
 15. The sensor assembly of claim 13, wherein the rib memberhas a generally rectangular cross-section.
 16. The sensor assembly ofclaim 13, wherein the rib member is provided with a concave tipproximate the pressure sensor.
 17. The sensor assembly of claim 13,wherein the rib member is provided with a convex tip proximate thepressure sensor.